disabling gpo for automatic update for a few clients

have a gpo for automatic updates that will install any needed patches
on a specific evening from an internal wsus server. most of the time
this works fine but occassionally we need to stop this for a handful of
servers (windows 2000 and 2003). if i disable the automatic update
service it just gets re-enabled again due to the gpo. think the only
way around this may be to set a deny permission on the gpo for the
specific servers or to use wmi filtering. anyone know of another way
??